Analog Window Integrator With Adjustable Impedance for Sidelobe Noise
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Solution Overview
Problem
Existing window function processing modules in communication and capacitive touch control systems suffer from noise introduced by sidelobes, which lower the Signal-to-Noise Ratio (SNR) due to high output frequencies requiring high sampling rates, increasing power consumption and circuit complexity.
Innovation Solution
An analog integrating circuit with an adjustable impedance module, controlled by a control unit to adjust integration gains at different time intervals, effectively applies a window function to suppress sidelobe noise, reducing the need for high sampling rates and simplifying the circuit design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a digital integrator is used to apply window function, then the sidelobe noise is suppressed and SNR is enhanced, but the output frequency becomes high requiring high sampling rate which increases power consumption and circuit complexity
Solution Approach 1:
The patent replaces the digital integrator (electronic/digital system) with an analog integrator circuit that directly applies the window function in the analog domain. This substitution eliminates the need for high-frequency digital processing, thereby reducing the sampling rate requirement and lowering power consumption while maintaining SNR enhancement through window function application.
Solution Approach 2:
The patent changes the operating domain from digital to analog, and modifies the integration gain parameter dynamically according to the window function requirements. By adjusting the integration gain in the analog domain rather than processing high-frequency digital signals, the system achieves the same noise suppression effect with lower power consumption and reduced sampling rate requirements.
2Reliability
If a digital integrator is used to apply window function, then the sidelobe noise is suppressed and SNR is enhanced, but the circuit complexity increases due to high sampling rate requirements
Solution Approach 1:
The patent replaces the complex digital integrator system with a simpler analog integrator circuit. This substitution eliminates the need for high-speed digital processing components and high sampling rate ADCs, thereby reducing overall circuit complexity while maintaining the SNR enhancement benefit through analog window function application.
Solution Approach 2:
The patent extracts the window function application from the digital processing domain and implements it separately in the analog domain before ADC conversion. This extraction allows the digital system to operate at lower sampling rates, simplifying the digital circuit complexity while the analog window function circuit handles the noise suppression function.
3Ease of operation
If square wave or sinusoidal wave is used in mixer, then the mixing function is achieved, but sidelobe is generated which introduces noise and lowers system SNR
Solution Approach 1:
The patent applies the window function in advance, before the integration process, to pre-suppress the sidelobe noise generated by the square wave or sinusoidal mixer. By performing this noise suppression action preliminarily in the analog domain, the subsequent digital processing receives a cleaner signal with reduced sidelobe artifacts, improving overall system SNR.
Solution Approach 2:
The patent converts the harmful sidelobe noise from the mixer into a manageable signal characteristic by applying the window function. The window function transforms the spectral characteristics of the mixer output, redistributing the energy from sidelobes into the main lobe, thereby converting the harmful noise into useful signal energy that can be properly processed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution reduces noise from sidelobes, enhances SNR, and decreases the power consumption and complexity of the overall circuit by performing window function operations in the analog domain, rather than the digital domain.
Implementation Method 1
the adjustable impedance module is controlled by at least one control signal to adjust an impedance value of the adjustable impedance module, and the impedance value is related to an integration gain of the integrating circuit
Implementation Method 2
the integrating circuit includes an operational amplifier
Implementation Method 3
an integrating capacitor coupled to an output terminal and a first input terminal of the operational amplifier
Data Source
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AI summary
The present application provides a window function processing module including an integrating circuit, configured to receive an integrating input signal, the integrating circuit comprising an operational amplifier; an integrating capacitor, coupled to an output terminal and a first input terminal of the operational amplifier; and an adjustable impedance module, coupled between the first input terminal of the operational amplifier and an integrating input terminal of the integrating circuit, wherein the adjustable impedance module is controlled by at least one control signal to adjust an impedance value of the adjustable impedance module; and a control unit, coupled to the integrating circuit, configured to generate the at least one control signal according to a window function, to adjust the integration gain of the integrating circuit, such that the integrating output signal is related to an operation result of the integrating input signal and the window function.